As a freshman in 2016, Costes served as the Terps' regular left fielder. He hit .263 in 54 games and led the team with a .479 slugging percentage, earning a spot on the Big Ten All-Freshman team.

Costes broke out as a sophomore in 2017. He started all 61 games and garnered first-team All-Big Ten honors on the strength of a .322 batting average, .429 on-base percentage and .548 slugging percentage. The Astros picked him in the 25th round of that year's draft, but he chose to return to Maryland for his junior year.

That decision appeared to backfire, as Costes struggled throughout his third collegiate season. His batting average plummeted to .235, and he slugged just .374. In April, the team suspended him for its series against Purdue, which coach Rob Vaughn said was due to a violation of team rules.

Still, the Astros decided to choose Costes again — and at a higher round, too. With one year of eligibility remaining, he can return to College Park to boost his stock, or sign with Houston before the July 6 deadline.